Disposable bracelets have long been used for such things as identification, access control, age verification, among other purposes. Such bracelets have typically been made from materials such as polyester, paper, or vinyl. The physical presence of a bracelet of particular color or design is traditionally used as its identifier. For example, such bracelets have been used in water parks and theme parks to quickly and uniquely identify patrons who have already paid for admission, or to control access to restricted areas. A patron of legal drinking age could obtain a bracelet to indicate that the patron is of legal age, granting the patron access to restricted areas such as beer sales areas.
In recent years, such bracelets have been augmented with Radio Frequency Identification (RFID) technology. RFID extends the usefulness of such bracelets, as they can each be programmed with a unique code that quickly and easily identifies the wearer. RFID also adds new functionality to such bracelets. As one example, they can be used to locate the wearer. Thus, with the installation of appropriate radio location equipment, a lost child wearing an RFID bracelet can be easily located or prevented from leaving an amusement park unless accompanied by an authorized adult.
RFID bracelets are also used to allow the purchase of items without the exchange of currency or need for a credit/debit card, or to allow secure communication and monetary exchange among patrons (for example, a parent may authorize credit of funds to a child to allow a purchase up to a preselected amount). Upon entering a park or other venue, a patron can request that the bracelet issued to the patron or the patron's family members be credited for purchases up to a preselected amount. Purchases up to the preselected amount can then be made using the bracelet instead of using cash or credit/debit cards. The bracelet can also be coded so that a wearer would be prevented from making certain purchases, or from making a single purchase above a chosen limit, so that children, for example, are encouraged to spend their allotted funds wisely.
RFID bracelets of the type described above are most often made to be disposable, so that they are inexpensive to produce and easy to use. However, such bracelets are susceptible to misuse and unauthorized use. Some bracelets are easy to remove, yet still function after removal. A bracelet that still functions after it has been removed provides the opportunity for patrons to exchange bracelets. This could provide patrons with the opportunity to give access to a restricted area to an unauthorized patron. A patron issued an “adult” bracelet that allows access to beer sales, for example, could remove and give or sell that bracelet to a patron not of legal drinking age. As another example, a thoughtlessly discarded bracelet that still has funds credited to it could be retrieved and used by an unauthorized individual to purchase goods or services using someone else's account.
A bracelet that is rendered non-functional after removal destroys its value for transfer to another patron, and would safeguard against unauthorized use of bracelets.
A number of mechanical measures have been taken to prevent such bracelets from being transferred. One approach is a single-use locking button mechanism found on some plastic bracelets. An example of this approach is found in U.S. Pat. No. 5,973,600. Also known are adhesive locking mechanisms with slits that prevent the wearer from peeling the adhesive back and reattaching it. An example of that approach is found in U.S. Pat. No. 6,474,557.
Those mechanisms render tampering with the lock or adhesive obvious to a visual inspection of the bracelet and, in most cases, render the bracelet unwearable after removal. However, tampering with the band portion of the bracelet is not prevented by those mechanisms. It is still possible for the bracelet to be cut or torn, and reattached with a simple piece of transparent tape or glue. To detect this sort of tampering, the person checking the bracelet would need to either make a full visual inspection of the bracelet or tug very firmly on the bracelet. This is slow, inconvenient, and impractical, especially when large numbers of people require identification. Furthermore, such a visual inspection is subject to human error, the most obvious being the failure of the bracelet checker to perform adequate inspection.
The use of RFID technologies has thus made the process of identifying the bracelet wearer faster and more secure, resulting in an increased use of bracelets for identification purposes and for facilitating transactions. However, this can lead to complacency among those responsible for inspecting bracelets, and has a tendency to reduce the likelihood that the person checking the bracelet wearer will perform an adequate visual or physical inspection.
Special electronic bracelets that prevent transferability for ensuring that hospital patients or prisoners remain within a given proximity of their quarters are known. However, such designs are prohibitively bulky, expensive, and overly complex for use in high-volume applications with short-term use. For example, U.S. Pat. Nos. 5,471,197 and 5,374,921 disclose the use of fiber optics to ensure that the bracelet is not removed. U.S. Pat. No. 6,144,303 describes a capacitive coupling between the bracelet and the wearer's skin. When the capacitance changes, indicating bracelet removal, an alarm is tripped. But the methods and devices disclosed in those patents are unnecessarily complex and prohibitively expensive for disposable use.
U.S. Pat. Nos. 4,973,944 and 4,980,671 describe bracelets with DC current paths that run around the bracelet and form a closed circuit when the ends of the bracelet are brought together. This method involves complications when attempting to use it with conventional disposable bracelet designs, as it requires a large metal contact area to enable size adjustment of the bracelet. It also does not necessarily solve the problem of tampering because such bracelets are designed to activate an alarm when removed, not necessarily to prevent reattachment. The metal to metal contact surfaces could be easily reattached on a limb of a different user.
Certain prior art disposable identification bands have been made tamper resistant by including a disabling wire in the band. For example, a co-pending U.S. patent application Ser. No. 10/400,049 on Mar. 26, 2003 by Girvin, J., and Lerch, J., entitled “Non-Reusable Identification Device”, assigned to Proximities, Inc., the assignee of the present application, a disabling wire is run along the band and is arranged to disable an RFID transponder if the wire is cut.